Machine foe slating coal



UNITED sTATEs PATENT oEEroE.

T. GARRETSON, OF POTTSVILLE, PENNSYLVANIA.

MACHINE FOR SLATINGi- COAL.

Specification of Letters Patent No. 119,768, dated March 30, 1858.

To all whom it may concern.'

Be it known that I, T. GARRETsoN, of Pottsville, in the county of Schuylkill and State of Pennsylvania, have invented a new and useful Improvement in Machines for Slating Coal; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1, is a longitudinal vertical section of a coal slating machine with my improvement. Fig. 2, is a transverse vertical section of the same. Figs. 3 and 4 are transvers sections of modifications of the cylind rical screen.

Similar letters of reference indicate corresponding parts in the several figures.

This invention consists in a certain construction of the sides of a rotary screen and of the openings in t-he said sides which encourages and permits the escape through the said openings of pieces of thin flat form like the pieces of slate in broken coal, but not of lumps like coal.

To enable others skilled in the art to make and use my invention I will proceed to describe its construct-ion and operation.

The rotary screen shown in Figs. 1 and 2 is constructed of two strong open circular or annular heads A, A, of cast or wrought iron which form the ends thereof united by a number of straight bars B, B, and a corresponding number of plates C, C. The bars B, B, are arranged in a circular or cylindrical form at equal distance apart and at equal distances from the center of rotation of the screen, and the plates C, C, are arranged tangentially to an imaginary circle or cylinder inscribed within the bars B, B, each one starting from one of the bars with its inner face even with the inner side of the bar and passing some distance outside of the next bar so as to form openings a, a, outside of the several bars B, B, to which openings the inner surfaces of the plates C, C, constitute conductors. These openings diler from the openings in other screens, for the same purpose in not leading directly outward through the sides of the screen, but leading in a tangential direction. The rotary screen thus constructed may be fitted with a central axle D, as represented which can be arranged to run in any suitable bearings, or it may have its circular ends A, A, supported on rollers, so that it may be capable of rotation, and the said screen may be arranged withon a box E, or 1n a frame. The coal is intended to be fed to it at one of its open ends, and, after having the slates extracted by making their escape through the openings in the sides, to be discharged at the opposite end. To facilitate this operation the screen should have its axis slightly inclined as is common to other screens for the same purpose. The

rotation lof the screen is in the direction of the arrow shown on it in Fig. 2, which is contrary to the openings a, a. When the screen is rotating the coal and slate receive such a motion together that, the slate being atter and heavier than the coal, has a tendency to slide under the coal and work to the bottom thereof and then it slides easily down the inner surfaces of the rising plates C, C, and through the openings a, a, while the sliding of the coalis checked by t-he bars B, B. As the screen rotates the slate that passes one opening will work its way to t-he succeeding ones as they present themselves in a favorable position. The dirt escapes through the openings with the slates and in cleaning wet coal this construction of the screen is of special advantage as the flat pieces passing through the long openings force out the wet dirt and prevent it clogging, as it is almost sure to do on checkered openings.

The modification of the screen shown in Fig. 3, only differs from that shown in Figs. l and 2 in having the plates C, C, curved instead of flat so as to form eccentric arcs but yet approximating to tangents to an imaginary circle or cylinder inscribed within or described through the bars B, B. I do not regard this modification as possessing any advantages over the construction first described but merely represent it as an equivalent.

The modification shown in Fig. 4, consists in substituting a series of barsv C C, for each plate C, to constitute surfaces like the interior of the said plates to form conductors to the openings a, a. Thesse bars may be arranged as tangents like the plates in Fig. 2, or as eccentric arcs like the plates in Fig. 3. The openings between the bars C', C, are to be quite narrow so as only to ermit t-he escape of Adirt and not to interfere with the sliding of the slates toward the openings a, a. The openings a, a, in all the modifications described have the same tangential direction and are outside of the bars B, B, Which may be considered as guards to prevent the exit of the coal but permit*` the escape of the slate.

What I cla-im as my invention and desire to secure by Letters Patent, is-

The construction of the sides of the screen and the openings a, a, therein substantially as described to bring the said openings out- 

